Fixture for relief grinding of cutting tools



E- E- PARKER FIXTURE FOR RELIEF GRINDING 0F CUTTING TOOLS Filed July 14, 1947 Jan. 16,1951

2 Sheets-Sheet 1 VIII/2% ilallllllrnl II INVENTOR. .EMMETT EPARKER ATTOR NEYS un h H I.

Jan. 16, 1951 E. E. PARKER FIXTURE FOR RELIEF GRINDING OF CUTTING TOOLS Filed July 14, 1947 2 Sheets-Sheet 2 C II INVENTOR. EMMETT EPARKER ATTOR NEYS Patented Jan. 16, 1951 FIXTURE FOR RELIEF GRINDING F CUTTING TOOLS Emmett E. Parker, Farmington; Mich, assignor to Midwest Tool & Manufacturing Company, Detroit, vlliliclr, a corporation of Michigan Application-July 14, 1947, Serial No. 760,757

4 Claims.

1 The invention relates to apparatus for use in cooperation with a grinding machine for the relief grinding of cutting tools. It is the primary 3 object of the invention to obtain a simple -con- :s'truction of mechanism .by which the tool may be rotated and simultaneously moved axially or With these :objects in view the invention consists in the construction as hereinafter set forth.

In the drawings:

1 is a plan view :of the fixture;

Fig. 2 is a Side elevation thereof partly in section;

Fig. 3 is an end elevation; and

.Fig. 4 is a section on the line 2- 2,, Fig. 2.

My improved fixture comprises a base portion l0 preferably provided with slotted rears. M at opposite ends thereof for use :in clamping it to the table of a grinding machine. It is further provided with depending lugs .12 for engagement with channels in the grinding machine table to seat the base in proper angular relation thereto. Projecting upward from the base are spaced lugs 13 for the mounting of a shaft or pin M extending therebetween. ISecured to the pin 14 and between the lugs i3 is .a rocker member 15 which longitudinally is .of T-shaped form. The upper portion or head of the T is bored to receive a shaft 16. Annular race members H are placed "in counterbores at opposite ends of the T and balls 18 in cage members 19- are placed intermediate the shaft and the race members. These form anti-friction ibea-rings which permit both rotary and axial movement of the shaft within the rocker IS. The shaft 16 projects beyond the rocker at both ends and the portion to'the'right, Figs. 1 and '2, is provided with an enlarged head 20 having an inwardly tapered recess therein for receiving an adapter member 21!. This is secured by means of a threaded shank .22 engaging a correspondingly threaded bearing in a closure head 23 at the end .of the member 15. The adaptor is further provided witha plug 24 having an internal threaded engagement with the shank .22 and this plug has an axially threaded bore for engaging a threaded stop member 25. The latter is used for positioning the shank of the "tool in the adaptor; said shank being then secured by a set .sctrew 25. The opposite projecting end .portionof the shaft .116 has detach-ably secured thereto a wheel 2? 36 mounted on a pin '3].

2 with a crank handle 28 which may be used for rotating the shaft in its bearings. Intermediate this wheel and the rocker i5 there is secured to the shaft a pair of exchangeable cam members 29 and Eli, both of which .are keyed to rotate with the shaft. These cams are clamped against a shoulder 3-! on the shaft by means of a clamping nut 32 engaging a threaded portion 33 of said shaft, a helical spring 34 is sleeved on the shaft between the cam 30 and a :head of the member 15. At :one end of the base to the left, Figs. 1 and 2, is a standard or column 35 which is bifurcated at its upper end to receive a roller This roller forms a bearing for cooperation with the cam 36 and is of sufiicient length to remain in engagement with said cam during the maximum axial movement of the shaft. The cam 29 is fashioned to :actuate the shaft in an axial direction and to this end is provided with a series of axially projecting cam portions adjacent to the periphery thereof. These cam portions cooperate with a roller member 38 mounted on .a vertical pin 35 which is secured in a bifurcated return bent plate member it. The latter is secured to the top of the member 15 by clamping screws 41 passing through slots 42 in the plate. This permits of adjusting the plate longitudinally in relation to the cam and also removing the plate to avoid interference when cams are exchanged. The member I5 has projecting laterally therefrom on opposite sides of the axis of the pin I4 lugs 43 and M which are spaced above the base member l0. Beneath the lug 43 there is secured to the base a post 45 and a screwtfi secured to said lug and contacting with said post forms a means for limiting movement of the rocking member I5 in one direction. Rocking movement in the opposite direction is limited by a block 47 beneath the lug M, but this block is secured to a headed pin 43 the head of which engages .a T-slot 49 extending longitudinally of the base Ill. Thus the block 41 may be adjusted longitudinally on the base so as to clear the lug 44 and permit the rocking movement of the member IS. A helical spring eta surrounding the post A5 and bearing against the .lug l3 yieldably presses the cam .38

against theroller 36.

Operation shaft It by selecting a proper adaptor 2| for receivin the same and mounting this in the tapered socket of the enlarged head 20. Cams corresponding to the particular tool are then selected and mounted upon the shaft IS first removing the wheel 27 and the plate 4i). Both cam members 29 and 39 have the cam portions thereof corresponding in number to the cutting edges between flutes or gashes in the tool. The cam portions on the member 39 are on the periphery thereof extending radially outward, while the cam portions on the member 29 extend axially. When the cams are secured in position, the

wheel 2'? and plate 40 are replaced and the tool is rotatably adjusted in its holder (by suitable means, not shown) for proper registration with the cams. It is to be .understood that the grinder wheel (indicated by dotted lines, Fig. 1) has been trimmed to the proper form and as indicated it has a grinding face 5!, for a lonshaft It by means of the'wheel 21 and crank handle 23. During such rotation the cam 36 will rock the member i5 against the resilient pressure of the spring 45a which will move the tool radially towards the surface 5| of the grinder wheel and thus will grind radial relief in rear of each cutting edge. At the same time the cam 29 will move the shaft axially so that the grinding surface 52 will grind axial relief adjacent to the cutting edges in the shoulder portion of the tool. for all of the cutting edges of the tool during a complete revolution of the shaft 16.

What I claim as my invention is:

l. A fixture for relief grindin of cutting tools, comprising a base, a member rockably mounted on said base and provided in its upper portion with a bore having its axis parallel to the rocl ing axis, a shaft extending through said bore, caged ball bearings within said bore engaging said shaft with universal freedom for simultaneous rotation and axial movement thereof, a tool holder at one end of said shaft axially aligned therewith, a handle for rotating said shaft at the opposite end thereof, a pair of abutting exchangeable cams detachably mounted on said shaft external to said rockable member and corresponding to the tool mounted in said holder,

one of said cams being adapted to rock the rockable member and shaft carried thereby and the other cam imparting axial movement to said shaft, bearings cooperating with said cams and resilient means for pressing said cams against their respective bearings.

2. A fixture for relief grinding of cutting tools, comprising a base, a T-shaped rockable mem-' her having its lower end pivoted upon said base and its upper portion or head of the T having a bore therethrough parallel to the axis of said pivot, a shaft extending through said bore and In this manner relief will be ground tions corresponding in number to the cutting edges of the tool to be ground, the cam portions of one of said cam members extendin radially and those of the other cam member extending axially, a roller mounted on said base engaging one side of the cam member having the radially extending cam portions, resilient yieldable means for rocking the rockable member in a direction to press said cam against said roller, a roller for engaging the cam having the axially extending cam portions, a member in which the latter roller is mounted secured to said T-shaped member and a spring sleeved on said shaft between the said rockable member and said cams for yieldably pressing the cam with axially extending portions against the cooperating roller.

3. A fixture for relief grinding of cutting tools, comprising a base, a T-shaped rockable member having its lower end pivoted upon said base and its upper portion or head of the T having a bore therethrough parallel to the axis of said pivot, a shaft extending through said bore and beyond the same at each end of said T-shaped member, caged ball bearings within said bore at opposite ends thereof for holding said shaft with universal freedom for simultaneous rotation and axial movement thereof, a tool holder at one end of said shaft in axial alignment therewith, means for rotating the shaft at the opposite end thereof, a pair of exchangeable cam members detachably mounted on said shaft adjacent to each other and external to said T- shaped head each having a series of cam portions corresponding in number to the cutting edges of the tool to be ground, the cam portions of one of said cam members extending radially and those of the other cam member extending axially, a roller mounted on said base engaging one side of the cam member having the radially extending cam portions, resilient yieldable means for rocking the rockable member in a direction to press said cam against said roller, a roller for engaging the cam having the axially extending cam portions, a member in which said roller is mounted secured to said T-shaped member and'a spring sleeved on said shaft between the said rockable member and said cams for yieldably pressing the cam with axially extending portions against the cooperating roller, and means for exactly positioning and locking said rockable member against rocking movement when only axial relief is to be ground.

4. A fixture for relief grinding of cutting tools, comprising a base, a T-shaped rockable member having its lower end pivoted upon said base and its upper portion or head of the T having a bore therethrough parallel to the axis of the pivot, a shaft extending through said bore and beyond the same at each end of said T-shaped member, ball bearings within said bore at, opposite ends thereof for holding said shaft with freedom for rotation and axial movement thereof, a tool holder at one end of said shaft in axial alignment therewith, means for rotating the shaft at the opposite end thereof, a pair of exchangeable cam members detachably mounted on said shaft adjacent to each other and external to said T-shaped head each having a series of cam portions corresponding in number to the cutting edges of the tool to be ground, the

cam portions of one of said cam members extending radially and those of the other cam member extending radially, a roller mounted on said base engaging one side of the cam member having the radially extending cam portions,

resilient yieldable means for rocking the rockable members in a direction to press said cam against said roller, a roller for engaging the cam having the axially extending cam portions, a member in which said roller is mounted secured to said T-rshaped member, a spring sleeved on said shaft between the said rockable -member and said cams for yieidably pressing the cam with axially extendin portions against the cooperating roller, lugs projecting from opposite sides of said rockable member above said base, a spring between said base and one of said lugs, a block between the opposite lug and the base for holding said rockable member stationary and exactly positioned, and attachment means be-' 15 tween said block and base permitting movement of the block from beneath the lug to free said rockable member for rocking movement.

' EMMETT E. PARKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 1,323,452 Cogsdill Dec. 2, 1919 2,099,724 Cogsdill Nov. 23, 1937 2,413,436 Dawson Dec. 31, 1946v 2,445,194 Umbdenstock Ju1y 13, 1948 

